1. Field of the Invention
This invention relates to a door latch adapted for mounting in an opening in a door panel, especially metal door panels of cabinets housing electrical equipment, such as for example, load centers. More particularly, it is directed to a one-piece polymeric door latch having an integral spring which engages the edge of the opening in the door panel and biases the latch to the latched position.
2. Background Information
Various enclosures with doors commonly employ a sliding latch to retain the door in the closed/latched position. Typically, the door latch utilizes mechanical fasteners for securement to the door, and a metal spring to automatically return it to the latched position. Mechanical fasteners and springs are costly to procure, store and assemble. Expensive insertion equipment is also required to install such fasteners.
A simple, effective, existing door latch for metal cabinets, such as electrical load centers, has a polymeric base member which covers and slides relative to a latch opening in the metal door panel. An actuator molded integrally with the base member extends through the opening and has projections on each side which engage the underside of the door panel. A molded latch hook projects from the actuator toward the door jam. The latch is biased toward the door jam by a separate, stamped metal spring which clips onto the edge of the opening in the door panel and bears against the actuator. The actuator has a finger pocket which is engaged to slide the latch member toward the unlatched position. The metal spring automatically returns the latch to the latch position when released. Other types of separate metal springs such as coil or wire springs are used in similar types of door latches. As mentioned, metal springs are costly. They are also subject to hydrogen embrittlement resulting from the plating process. It is not unknown for such springs to break during storage before the latch is even put into use.
Another existing load center has a polymeric door with integrally molded ribs which provide a spring force biasing a polymeric sliding latch toward the latched position.
There is a need for a door latch having a spring which is not subject to embrittlement.
There is also a need for a door latch which does not require a separate metal spring and the tools required to install such a door latch.
There is a further need for an improved door latch which is easy and inexpensive to manufacture.
There is still another need for an improved door latch with all the above characteristics which can be used with a thin door panel, such as a metal door panel.